Tensile lap shear strength is a value that represents an adhesive's ability to form and hold an adhesive bond. This value is determined by bonding together two pieces of substrate (aluminum is the most common test substrate material) with the adhesive, and then measuring how much force is required to break the bond. For most applications, choosing an adhesive with a higher lap shear strength means choosing the stronger adhesive. For this reason, developing an understanding of typical lap shear values is critical.In this post we will compare the lap shear values of three polymer adhesives. All three adhesives have been developed by polymer formulator and supplier Resin Designs. By comparing the lap shear values of these products we will be able to better understand this metric.
Acura 80201 - 900 psi
Acura 80201 is an electrically conductive epoxy adhesive. This epoxy compound was able to withstand 900 psi before failing the lap shear test. 900 psi is on the relatively low end for an epoxy adhesive. As an electrically conductive epoxy, acura 80201 is highly filled with silver, which takes away from the ultimate adhesive strength of the polymer structure. In general, highly filled epoxies will not perform exceptionally well on a lap shear test, however, they generally offer a unique property in return such as thermal or electrical conductivity.
Nexus 84211 - 2,500 psi
Nexus 84211 is a more traditional epoxy adhesive, falling towards the middle of the spectrum. This epoxy is oriented towards adhesive performance rather than a specialized performance property. Most epoxies fall in the 1,000-2,500 psi range.
Nexus 84301 - 4,000 psi
Nexus 84301 is a high performance epoxy adhesive, offering some of the highest levels of lap shear strength an epoxy can offer. This toughened industrial epoxy is modified with non-reactive solid species that act to efficiently allocate stress throughout the polymer structure (hence toughening the epoxy). Toughened eoxies like Nexus 84301 are designed for high stress applications. Custom systems can be specially formulated to withstand up to 10,000 psi.